Illustrated Articles

Dogs + Infectious Diseases

  • Heartworm disease or dirofilariasis is a serious and potentially fatal disease. It is caused by a blood-borne parasite known as Dirofilaria immitis. Treatment usually consists of several parts including an injectable drug to kill adult heartworms, antibiotics, and treatment to kill microfilaria. There is some risk involved in treating dogs with heartworms, although fatalities are rare.

  • Hepatozoonosis is a disease caused by a protozoan (a small, microscopic organism) known as Hepatozoon. There are two species that cause hepatozoonosis, Hepatozoon canis and H. americanum, and there are differences in the course of disease and treatment depending on which species is the cause of the disease. Both species are spread by ticks; the most effective method to prevent hepatozoonosis is the regular use of an effective tick prevention.

  • Canine herpesvirus or canine herpes is a systemic, often fatal disease of puppies caused by canine herpes virus. It may remain latent in tissues after a dog is infected and may be passed on to other dogs, particularly to fetuses developing in the mother's uterus. Clinical signs in puppies include difficulty breathing, nasal discharge, anorexia, soft stools, crying, seizures, and sudden death. Symptoms in adult dogs include coughing and sneezing, miscarriage, lesions on the external genitalia, conjunctivitis, and corneal ulcers. Disease may be prevented by avoiding contact with infected dogs. Pregnant dogs should be isolated to prevent infection.

  • Histoplasmosis is an infection caused by histoplasma, a fungus found in moist soils and especially prevalent around the Ohio, Mississippi, Missouri, and St. Lawrence Rivers, as well as the southern Great Lakes. Fungal spores are inhaled or ingested and cause infection in many sites including the lungs, gastrointestinal tract, eyes, joints, and spleen. Clinical signs can include fever, lethargy, anorexia, weight loss, coughing or trouble breathing, diarrhea, and straining while defecating. Diagnosis includes routine bloodwork, urinalysis, X-rays, antigen testing, and cytology or histopathology. Treatment requires long term anti-fungal medication such as itraconazole. Prognosis is guarded depending on how ill the patient is. This disease is transmissible to humans, especially if they are immunocompromised.

  • Hookworms are intestinal parasites of the cat and dog that get their name from the hook-like mouthparts they use to anchor themselves to the lining of the intestinal wall. A large number of hookworms can cause inflammation in the dog's intestine as well as a life-threatening decrease in the number of red bloods cells, which is called anemia. This problem is most common in puppies, but can occur in adult dogs.

  • Vaccinations are important to prevent serious illness in dogs. Even dogs that spend 100% of their time indoors should be vaccinated. Some viruses can be carried into your home on inanimate objects such as shoes and clothing, therefore infecting your dog without him coming into contact with another animal. Rabies is deadly for both dogs and humans and can be transmitted by a rabid bat that makes its way into your home. Your veterinarian is your most important resource in determining what vaccinations need to be given to your dog to keep him protected.

  • Hepatitis is defined as inflammation of the liver. As a specific disease, infectious canine hepatitis (ICH) is a viral infection. The hepatitis virus is present in the urine, as well as in the nose and eye discharges of infected animals and the virus is transmitted by direct contact with these infected materials. In the mild form the dog may merely have a decreased appetite, appear depressed, and have a mild fever. Treatment is aimed at reducing symptoms and giving time for the dog's immune system to respond. Vaccination has been very successful at reducing the prevalence of this disease.

  • Kennel cough is a broad term covering any infectious or contagious condition of dogs where coughing is one of the major clinical signs. It is also referred to as infectious tracheobronchitis. Several viruses and bacteria can cause kennel cough, often at the same time. Because the infection spreads when dogs are housed together, it is often seen soon after dogs have been in kennels, hence the name 'kennel cough'.

  • Leishmaniasis is a serious condition spread by flies that can affect dogs, cats, and people. It can severely damage the internal organs or skin and even with treatment, the outcome is often not successful.

  • Leptospirosis is a bacterial disease of dogs and other mammals that primarily affects the liver or kidneys. The bacteria (Leptospira) that cause leptospirosis, commonly called leptospires, thrive in water. Infected or recovered carrier dogs may act as a source of the infection. There are three main forms of the disease. Antibiotics such as penicillin, ampicillin, and amoxicillin, are reasonably effective against the acute stages of leptospirosis if begun early, although most affected dogs require intensive care in the veterinary hospital.